async-h1 is an asynchronous HTTP/1.1 parser for Rust (crates.io). There is a request smuggling vulnerability in async-h1 before version 2.3.0. This vulnerability affects any webserver that uses async-h1 behind a reverse proxy, including all such Tide applications. If the server does not read the body of a request which is longer than some buffer length, async-h1 will attempt to read a subsequent request from the body content starting at that offset into the body. One way to exploit this vulnerability would be for an adversary to craft a request such that the body contains a request that would not be noticed by a reverse proxy, allowing it to forge forwarded/x-forwarded headers. If an application trusted the authenticity of these headers, it could be misled by the smuggled request. Another potential concern with this vulnerability is that if a reverse proxy is sending multiple http clients' requests along the same keep-alive connection, it would be possible for the smuggled request to specify a long content and capture another user's request in its body. This content could be captured in a post request to an endpoint that allows the content to be subsequently retrieved by the adversary. This has been addressed in async-h1 2.3.0 and previous versions have been yanked.
History

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2020-12-21T21:50:13

Updated: 2024-08-04T15:56:03.655Z

Reserved: 2020-10-01T00:00:00

Link: CVE-2020-26281

cve-icon Vulnrichment

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cve-icon NVD

Status : Analyzed

Published: 2020-12-21T22:15:13.407

Modified: 2021-02-16T17:16:16.193

Link: CVE-2020-26281

cve-icon Redhat

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